# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Little Rock Creek
Water Body ID: | CAR6268000020110817180956
Water Body Type: | River & Stream

DECISION ID | 32136 | Region 6
Little Rock Creek

Pollutant: | Benthic-Macroinvertebrate Bioassessments
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Benthic Community Effects is being considered for placement on the section 303(d) list under sections 3.9 and 3.2 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this indicator. The single sample exceeded the narrative objective, which uses the Index of Biological Integrity (IBI) is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions. This site scored a score of 30 which may indicate impaired conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this water segment on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample exceeded the Index of Biological Integrity (IBI) value of 40. There is insufficient information about the water quality for this area and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 5 samples is needed for application of Table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32136, Benthic-Macroinvertebrate Bioassessments | Region 6
Little Rock Creek
LOE ID: | 32032
Pollutant: | Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: | Population/Community Degradation
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: | The survey scored 30 on the IBI, which means this water body may be considered to have impaired conditions based on the bioassessment.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | The Index of Biological Integrity (IBI) is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions.
Guideline Reference: | A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Environmental Management. Volume 35, number 1 (2005): pp. 1-13
Spatial Representation: | Sampling was done at to following station: 626PS0171-Little Rock Creek
Temporal Representation: | Sampling was done on May 15, 2008.
Environmental Conditions: |
QAPP Information: | Samples were collected for the project titled 'Statewide Perennial Streams Assessment 2008' following SWAMP protocols and data were stored in the SWAMP database.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32137 | Region 6
Little Rock Creek

Pollutant: | Chloride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. The single sample does not exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. One single sample is insufficient to capture the seasonal and annual fluctuations in streamflow and chloride concentrations for this waterbody. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32137, Chloride | Region 6
Little Rock Creek
LOE ID: | 32245
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample collected did not exceed the water quality objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-19, the water quality objective for chloride in this water body is an annual average of 12.5 mg/L. Per the tributary rule, the SSOs for Little Rock Reservoir are used for this water body.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 626PS0171 in Little Rock Creek.
Temporal Representation: | Sample collected on 5/15/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32139 | Region 6
Little Rock Creek

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32139, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Little Rock Creek
LOE ID: | 44321
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Little Rock Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Little Rock Creek was collected at 1 monitoring site [ Little Rock Creek]
Temporal Representation: | Data was collected on a single day 5/15/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32140 | Region 6
Little Rock Creek

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32140, Nitrite | Region 6
Little Rock Creek
LOE ID: | 44343
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Little Rock Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nitrite as N.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Little Rock Creek was collected at 1 monitoring site [ Little Rock Creek]
Temporal Representation: | Data was collected on a single day 5/15/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32141 | Region 6
Little Rock Creek

Pollutant: | Nitrogen, ammonia (Total Ammonia)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. None of The single sample does not exceed the water quality objective, which is based on the 4-day chronic criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample does not exceed the 4-day chronic criteria and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32141, Nitrogen, ammonia (Total Ammonia) | Region 6
Little Rock Creek
LOE ID: | 32484
Pollutant: | Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample did not exceeded the water quality objective for unionized ammonia. Data were reported as as total ammonia as nitrogen and were converted to unionized ammonia before being compared with the objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan objective for unionized ammonia is a function of pH, temperature, and the presence of salmonids. The 4-day chronic criteria for unionized ammonia with salmonids present is 0.040 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The sample was collected at site 626PS0171.
Temporal Representation: | The sample was collected on 5/15/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32142 | Region 6
Little Rock Creek

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32142, Oxygen, Dissolved | Region 6
Little Rock Creek
LOE ID: | 33842
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Numeric data generated from 1 sample of Dissolved Oxygen concentrations had no exceedences.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | For waters with the beneficial use of COLD, the minimum dissolved oxygen concentration shall not be less than that specified in Table 3-6. COLD One Day Minimum: 4.0 mg/L
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One sample was collected from station 626PS0171 (Little Rock Creek).
Temporal Representation: | One sample was collected on 5/15/2008 at 9:17:00 AM.
Environmental Conditions: |
QAPP Information: | SWAMP QAPP
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32143 | Region 6
Little Rock Creek

Pollutant: | Specific Conductivity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. None of the sample exceed the water quality objective, which is the MCL of 900 us/cm. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32143, Specific Conductivity | Region 6
Little Rock Creek
LOE ID: | 44262
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Little Rock Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Conductivity(Us).
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for specific conductance is 900 uS/cm (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Little Rock Creek was collected at 1 monitoring site [ Little Rock Creek]
Temporal Representation: | Data was collected on a single day 5/15/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32145 | Region 6
Little Rock Creek

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | One line of evidence is available in the administrative record to assess this pollutant. The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist.The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. This single sample is insufficient to define the natural range of temperature (including diel, seasonal and annual varations) or to detect whether changes have occurred. 3. The single sample is insufficient to determine compliance with the objective under section 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32145, Temperature, water | Region 6
Little Rock Creek
LOE ID: | 44299
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Little Rock Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Water Temperature.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective for all surface waters states the following: The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Data for this line of evidence for Little Rock Creek was collected at 1 monitoring site [ Little Rock Creek]
Temporal Representation: | Data was collected on a single day 5/15/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32146 | Region 6
Little Rock Creek

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. The single sample was not used in the assessment because assessment against the water quality objective requires that the normal ambient pH of this waterbody be established. Since the normal ambient pH of this waterbody is not known, we can not determine if the water quality objective was exceeded or not. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. A single sample is not sufficient to capture the seasonal and annual fluctuations in the streamflow and the pH level of this waterbody. 3. It is unknown whether the single sample exceeds the objective or not beceasue evaluation against the water quality objective requires that normal ambient pH level of this waterbody be known. This sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32146, pH | Region 6
Little Rock Creek
LOE ID: | 33131
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There was 1 sample with a pH of 7.93. The normal ambient pH level for this water body is unknown and so it is unknown whether any exceedences occured.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units." (Lahontan Basin Plan).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 626PS0171 in Little Rock Creek.
Temporal Representation: | Sample collected on 5/15/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32144 | Region 6
Little Rock Creek

Pollutant: | Sulfates
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the water quality objective, which is an annual average, and per the tributary rule, applies the site specific objective for Little Rock Reservoir to evaluate this water body. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. The objective is based on an annual average and a single sample is not sufficient to calculate an annual average nor does it capture the seasonal and annual fluctuations of this pollutant in the waterbody. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32144, Sulfates | Region 6
Little Rock Creek
LOE ID: | 32246
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample collected did not exceed the water quality objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-19, the water quality objective for sulfate in this water body is an annual average of 16.5 mg/L. Per the tributary rule, the SSOs for Little Rock Reservoir are used for this water body.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 626PS0171 in Little Rock Creek.
Temporal Representation: | Sample collected on 5/15/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan